scala条件语句

scala的语句if else条件语句是有返回值的 ：

/**  if else 有返回值  **/
scala> var age = 30
age: Int = 30

scala> if(age > 18) 1 else  0
res0: Int = 1

scala> val isAge = if(age >18) 30 else 0
isAge: Int = 30




/**  if else 对变量赋值  **/
scala> var isAdult = 1;
isAdult: Int = 1

scala> if (isAdult > 0) isAdult = 18 else isAdult = 1

scala> isAdult
res3: Int = 18




/** 如果返回值类型不相同，则返回公共类型 **/
scala> val age = 1;
age: Int = 1

scala> if(age > 1) "adult" else 0
res4: Any = 0


/** if后面可以不跟else相当于else() **/

scala> if(age > 10) "audlt" 
res7: Any = ()

scala> if(age > 10) "audlt" else ()
res8: Any = ()




/** 通常情况if后面会有多条执行语句，可以用过{}作为代码执行语句块 **/
scala> if(age < 12){
     |     "children"
     | }else{
     |     "audlt"
     | }
res9: String = children



/** 命令行可以用 :paste 命令执行多行代码块**/
scala> :paste
// Entering paste mode (ctrl-D to finish)

val age = 12

if(age > 12){
    "children"
}else{
    "audlt"
}

// Exiting paste mode, now interpreting.

age: Int = 12
res3: String = audlt